Thermostatic switch



May 24, 1932. v W. W. RIEDEL 1,859,985

THERMOSTATIG SWITCH Filed Feb. 28. 1930 i Illllllm gin/vento@ y Patented May 24, 1932 UNITED STATES PATENT OFFICE WALTEIB RI'EDE'L, OF DAYTON,` OHIO, ASSIGNOR TO DELCO PRODUCTS CORPORATION, OF DAYTON, OHIO, A CORPORATION OF DELAWARE THmOSTATIC SWITCH Application led February 28, 1930. Serial No. 432,100.

This invention relates to improvements in thermostatically controlled switches.

It is among theobjects .of the present ni Further objects and advantages of thel present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment-of one form of the present invention is clearly shown.

In the drawings Fig. 1 is a plan view of the switch with the cover removed. Y Fig. 2 is a longitudinal sectional view of the switch taken along the line 2-2 of Fig. 1. Fig. 3 is a view of the switch similar to Fig.

2, however, yshowing the contacts in another relative position.

Fig.,4 is a transverse section taken along the line 4 4 of Fig. l. J Referring to the drawings, the numeral 20 designates the casing, made up of. any insulating material such as molded bakelite or the like. Two terminals are molded in this casing 20, one, designated by the numeral 2l, the other by the numeral 22. The terminal 21 extends into the inside of casing 20 and provides the stationary Contact 23 therein. The other terminal 22 extends inside the casing Lead wire 24 is also connected to one end of a usual'strip 26, preferably of mica. The strip Y 26 is carried by the post 27 formed inside the 45 casing20. Heatere1ement25isconnectedwith a bracket 28 through wire 29, said bracket being secured to the bottom of the casing -20 by a. screw 30. One end of a exible' arm 31 is clamped between the bracket 28 and the 50 bottom of the casing 20,' securely anchoring and has the lead wire 24 connected thereto.

this end of the arm 31 to the casing. The free end of the arm is hook-shaped as at 32, the portion 33 of the hook-shaped end being spaced from the portion 34 of thel arm. A. contact 35 is attached to the arm portion 34. This contact is urged Ainto engagement with the stationary contact 23 by the flexible arm 31. Bracket 28, as shown in Fig.4 4, is recessed as at 36 for receiving the lever 37. Intermediate the ends of the lever, tongues 38 are formed thereon which engage the bracket 28 and form the fulcrum point about which said lever 37 oscillates. 'lhe one end of the lever designated by the numeral 39 extends into the space between the portions 33 and 34 of the flexible arm 31. The opposite end of the lever 37 has one end of a pressure coil spring 40 attached thereto, the other end of said spring abutting against a block 41 which is pivotally supported by a tonguev 42 provided on the end of the casing 20. Spring 40 is adapted yieldably to urge the lever 37 into either one of two extreme positions,

.said lever being shown in one extreme position in the Fig. 2 and in the opposite extreme position in the Fig. In the position as shown in Fig. 2, spring 40 exerts a force upon the lever 37 to urge its end 38 into engagement with the portion 34 of arm 31 so that the contact 35 is urged into engagement with its cooperating, stationary contact 23. In the position -as shown in Fig. 3, lever 37 has the force of the spring '30 exerted thereon so thatv the end 3810i the lever engages the portion 33 of the arm 31 whereby said arm 3l is flexed to maintain its contact 35 out of engagement with the cooperating stationary contact 23.

A thermostatic member 50, in the form of a strip, is shown anchored at one end to the cover 5l, secured to the casing by screws 52.

` At normal temperatures the free end of the thermostatic strip is in spaced relation to thc'lever 30, as shown in the Fig. 2. This thermostatic vstrip 50, however, is arranged to flex at increased temperatures whereby the `free end thereof will engage the lever 30 and move it clockwise as regards Fig. 2. Thermostatic strip 50 moves the lever 30 in this direction against the eiect of the spring 40 until the lever 37 and spring 40 have aligned substantiallylongitudinally, after which any slight movement by the thermostatic strip toward the lever 37 will move the lever 37 beyond this longitudinal alignment, thereby permitting the force of the spring 40 suddenly to fiip or snap the arm 37 into the position as shown in Fig. 3, in which position the contacts are disengaged. While the arm 37 and the spring 40 are substantially in longitudinal alignment, the end 38 of the lever is positioned somewhere between the portions 33 Dand 34 of the iiexible arm 31 and, during this time, contact engagement is maintained by the flexible arm 31. However, as soon as the4 lever 37 is moved beyond this longitudinal.

aligns with a similar extension 75 in the switch cover 51. When in normal disconnected position as shown in Fig. 3, the switch may beclosed by the depression of button 7 0- which causes its stem portion 76 to engage with the end 39 of the lever 37 and move it so that spring arm 31 will move the portion 33 thereof to follow the end 38 of the lever 37 As soon as the lever 37 and spring- 40 have moved beyond their longitudinal alignment, the spring 40 will quickly snap the lever 37 counter-clockwise so that its arm portion 38 will engage the portion 34 of arm 31 quickly and securely to urge the contact 35 into engagement with the cooperating contact 23.

f during rthe operation of the device it is desired to discontinue it, th`en thestarting button 71 may be depressed, which causes its stem portion 77 to engage'with the thermostatic element 51, pushing said thermostatic element against the lever 37 and causing said lever to be moved so that the spring 40 may eventually snap it clockwise whereby its end -38 will engage the arm portion 33 to move the contact 35 out of engagement with its coopera-'ting contact 23.

The heating unit 25 is in'circuit across the lcontacts 23-and 35 so that excessive" current flowing across these contacts or through this circuit will cause said heating unit tb be heated beyond a predetermined degree at which it will cause flexing of the thermostat 50 tomove`v the lever 37 to break contactengagement.

Applicant. has provided a switch of simple design, made up of elements which may be produced commercially at la minimum expense of time and material.'-

The switch operates quickly to make and break thecontact engagement, thereby substantially eliminating arcing between said contacts. An adjusting screw 80 is provided in the cover 51 by which the thermostatic element 50 may b e properly adjusted so that its free end is normally always spaced from the lever 37.

While the form of embodiment of the present invention as herein disclosed, constitutes 'a preferred form, it is to be understood that engagement with the lever and operate itfrom one position to permit the resilient means quickly to shift said lever into the other position; and switching means separate from the thermostatic vmeans and the lever, said switching means comprising a fixed contact and a movable contact, said movable contact having a portion engageable by the lever` so as to be operated by said lever.

2. A thermo switch comprising, in combination, a pivoted lever capable of clockwise and counter-clockwise movement into two extreme ositions; resilient meansV engaging the'l said lever and adapted yieldably to urge said lever into one or the other of saidlextreme positions; thermostatic means, arranged in juxtaposition to said lever, and adapted at increased temperatures to engage the lever an'd move it from one extreme position into a position in which the spring may quickly shift said lever into .the opposite extreme position; and switching means comprising a xed contact and a movable contact supported upon a iiexible strip which'is adapted to be engaged by the lever to operate the movable contact.

3. A thermo switch comprising, in combination, a lever pivoted intermediate its ends; a spring engaging one end of the pivoted lever and yielfably urgin said lever in one or the other direction; a t ermostatic -stri arran ed to-flex in res onse to a chanvre.

other of said extreme positions; a thermostaticstrip anchored at one end, the free end thereof lymg in juxtaposition to said lever at normal temperatures, said strip being adapted to flex at increased temperatures to en.-

gage with the lever and move it from its onen ends, one end of said lever engaging the movable contact; a spring engaging the other end of the lever yieldably urges it into one or the other of its extreme positions in which lthe movable contact is maintained either in or out of engagement with its cooperating contacts respectively; and a thermostatic strip normally'engaged' from this lever, but arranged to ilexy at increased temperatures to engage with said lever and move it into a position in which the spring exerts a force in the same direction upon said lever, quickly to move the lever toward the extreme position in which the movable contact is' disengaged from its cooperating contact.

6. A thermo switch comprising, in combination, two cooperating contacts one of whichis movable relative to the other; a lever pivotally supported intermediate its ends; a lost motion connectionI between one end of the lever and the movable contact; a spring engaging the other end of the lever and yieldably urging it into'two extreme positions, in one of whlch said lever will maintain the movable contact in engagement with the stationary contact?, in the other extreme position said lever will maintain the movable lcontact out of enga ement with its'cooperating contact; and a t rmostatic member normally disenga d from the lever, but adapted at increasede temperatures to flex and engage thelever to move it against the eect of the spring into a position in which `said spring,v will quickly operate the lever todisengage the contacts.

7; A thermo switch -comprising, in 'combi-l nation, a casing; a contact insulatingly supported within said casing; a movable contact a flexible arm sup normally urging it into engagement with the Yeo stationary contact; a bracket securing the flexible contact carrying arm within the housing; a lever pivotally supported by said bracket; a lost motion connection between the flexible contact arm and one end of the i lever; a 'spring having its one end abutting against the housingand the other end engaging. the end of the lever opposite that rting said contact and engaging the flexible contact arm, said spring yieldably ur 'ng the lever into two positions, one of whic maintains the contacts in engagement, the other maintaining said contacts out of engagement; and a t ermostatic strip normally disengaged from the lever, but arran d to flex at increased tem ratures for engaglng the lever and moving 1t against the effect of the spring into a position in w'hich said spring will quickly urge the lever to strike the flexible Contact ,arm to disengage the contacts. f

8. A thermo switch comprising, in combination, two cooperating contacts, one of which is movable relative to the other; a iiexible arm carrying the movable contact, said flexible arm being provided with a hook end; a bracket securing the one end of the flexible arm; a lever pivotally supported by said bracket, one end of the lever extendin into the'hook end of the iexible arm, provi ing a lost motion connection between said lever and arm; a spring having one end engaging' the otherend of said lever, said spring urging said lever into one or the other of its extreme positionsin which the movable contact is maintained in or out of engagement with the stationary contact respectively; and a thermostatic element, spaced from the lever at normal temperatures but arranged, at inhaving its one free end'engaged by a spring,

one end of which is pivotally secured; a thermostat 'arranged to iex in response to increasing temperatures and engage said lever to move the toggle so that the spring will quickly shift the lever into another of its extreme positions; and a switchin means comprising a stationary contact an a fixed arm supporting a cooperating wntact, said fixed arm having an extending portionengageable by the lever to move the contact in accordance with the position of said lever.

In testlmony whereof I hereto aiiix-my 'signature. Y l

` WALTER W. RIEDEL.

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